HANDLING APPLES FROM TREE TO TABLE 23 



dried out. Earlier, it is soft and juicy. Frequently, rot fungi invade 

 the fruit through the dead skin. They make black or brown spots 

 of decay and soon destroy what is left of the apple. Blue mold and 

 Alternaria are the most common invaders of soft scald tissue. Jona- 

 than, Rome Beauty, and Mcintosh are the varieties most often 

 affected with soft scald, but it occurs sometimes on other varieties 

 as well. 



While much experimental work has been done on this disease, very 

 little has been discovered to explain its nature and cause, except 

 that it is a low-temperature disorder. As a result, no categorical 

 statements can be made regarding its control. In general, however, 

 its incidence appears to be reduced or prevented by early harvest and 

 prompt cold storage at 30° to 32° F. Delay up to 10 days or 2 weeks 

 in placing the fruit at 30° to 32° seems to increase the tendency to 

 the disease, but after longer delays the susceptibility of the fruit de- 

 creases. Well-matured or overmature fruit is more susceptible to soft 

 scald and should not be stored at temperatures below 36°. The dis- 

 ease is erratic in its occurrence and may be bad one year and absent 

 the next. 



Soggy break-down is most serious in Grimes Golden and Golden 

 Delicious and appears to be the manifestation in these varieties of 

 the same disorder exhibited by soft scald in others. Soggy break- 

 down differs from soft scald chiefly in its location, being typically a 

 disease of the flesh, whereas soft scald is confined to the skin and 

 adjacent flesh. Soft scald has a sharply defined margin in the skin; 

 in soggy break-down there is a more extensive involvement of the 

 flesh beneath, without the sharp margin between the sound and the 

 affected tissues (fig. 9, D). It seems to be associated with the same 

 storage conditions under which soft scald occurs. 



SCALD 



Scald occurs in storage and is a more or less generally diffused 

 browning of the apple skin. At first it is superficial, but eventually 

 the skin may become soft and slough off and then the flesh beneath 

 either dries out or is opened to infection by rot fungi. The green or 

 unblushed portions of the fruit are most affected, and immature apples 

 are more susceptible than those picked later. 



Scald can be understood best by thinking of it as a disease induced 

 by suffocation or auto-intoxication; that is, it appears to be caused 

 by products given off by the apple itself. The particular products 

 involved apparently are connected with the odorous constituents of 

 the apples. 



Scald itself affects the appearance and not the dessert or culinary 

 quality of the fruit. However, when scald is found, it means that the 

 further storage life of the fruit is limited because scalded skin is 

 dead and offers no further protection to the fruit. The disease is 

 likely to spread rapidly until almost all the surface, particularly the 

 green-colored areas, is involved. It does not ordinarily begin to 

 appear until 60 days or more after harvest and commonly is more 

 serious on apples in cold storage than on those in common storage. 

 Sometimes it does not become manifest until after the apples are 

 removed to a warmer temperature and usually it becomes more serious 



